RESTENOSIS AFTER PERCUTANEOUS TRANSLUMINA L ANGIOPLASTY .2. POSSIBILITIES FOR PHARMACOLOGICAL INTERVENTION

Reocclusion after percutaneous transluminal angioplasty is a major mec hanism contributing to morbidity of patients after catheterization. Un til now, pharmacological approaches to the prevention of restenosis we re mostly disappointing, as only the early phase of thrombotic reocclu sion, in which platelet activation is a major patho-physiological mech anism, could be treated with inhibitors of platelet aggregation and co agulation. Recently, several new approaches to the pharmacotherapy of restenosis have been introduced, for example thromboxane receptor anta gonists or synthase inhibitors, GPIIb/IIa antagonists and hirudin as n ew inhibitors of platelet aggregation and coagulation, PDGF antagonist s as inhibitors of intimal proliferation, and modulators of endothelia l cell function, some of which may be effective in the late phase of m yointimal proliferation. However, many substances that had been promis ing in experimental restenosis have proven ineffective in the first cl inical trials. More recently, molecular biological techniques are incr easingly used in experimental angioplasty. The role of these different approaches for the prevention of restenosis still has to be proven in clinical trials.